Originally Published: February 12, 2005 7:10 a.m.
Carpenters know the importance of preparation, as expressed in the saying, "Measure twice, cut once." A house painter, too, carries out the most important part of the work before a brush touches paint. Gardening is no different. The old adage, "Never put a $5 plant in a 50-cent hole," is one way of saying that soil preparation is not the time to skimp on your work. Many beginning gardeners learn this the hard way.
Pay attention to soil preparation. Even if plants are spilling out of your local garden centers, don't bring them home until your soil is ready. If you buy plants on impulse before the garden is ready, you'll either succumb to the temptation to plant without adequate soil preparation, or you'll have to tend the plants in their pots until the garden is ready.
The first step in preparing a garden site is general cleanup by removing rocks, sticks, stumps, and other debris. Especially important is to kill off existing weeds. When the area is relatively clean, lay out the boundaries of your site using string, rope, or, my favorite, a garden hose.
Now it's time to amend the soil. By amending the soil in your garden, you can improve the physical soil structure. Soil amendments typically consist of organics such as compost, aged manure, peat moss, leaf mold, or similar organic materials. Although soil amendments sometimes contain plant nutrients, the nutrient level is generally not high enough for this material to be considered fertilizer.
Because sand drains freely, beginning gardeners sometimes amend clay soil with sand in an effort to improve drainage. My grandfather taught me that by mixing sand and clay together you can make cement. It works the same way in your garden. Adding organic material to the garden soil makes the greatest improvements to all types of soils in the tri-city area.
Without organic matter, sandy soil can't retain water long enough for plant roots to use it. Clay soils, because of their tightly packed particles, are too heavy to drain water off.
Spade or till your soil to one shovel's depth. Never add more than 2 inches of organic matter to the soil at one time; larger quantities are hard to mix into the soil.
Alkaline soil or a high pH is a unique problem to this part of Arizona. Most pH samples I've seen over the years have come back in the 7.2 to 7.8 range. I have seen several pH tests above the 8.0 level which is pushing soil that is sterile. Part of this comes from our alkaline water, so the pH creeps up as the summer watering schedule kicks in.
This is part of the reason I don't like products like Miracle Gro fertilizers. This particular fertilizer is alkaline and pushes your pH up even higher than your natural tap water.
I like to turn into my soils a slow release fertilizer like Start-N-Grow from fertilome or Osmicote, also add Soil Sulfur. The fertilizer slowly releases over a three-month period and the Soil Sulfur naturally lowers my pH. This allows the fertilizer to do a better job.
You can expect better flowers with more vibrant colors. Better blues from your spruce, cypress, hollies, hydrangea, and better green foliage from the rest of your plants. I rarely add iron products to my garden because of the benefit of Soil Sulfur.
If you have really hard soil consider adding gypsum and perlite to your soil. Gypsum is an all-natural product that helps flush soil of harmful salts that build up and cause drainage issues later in summer. In my opinion gypsum is a must in the tomato garden. The added calcium in the soil will reduce the likelihood of blossom-end rot, that ugly black spot that forms on a newly developing tomato in spring.
Perlite is my favorite for flower and vegetable gardens. I found it made a tremendous difference when I gardened in Prescott Valley. You may have noticed white specks in a good potting soil, that is perlite. It's an organic material that helps keep a hard soil from compacting and increases oxygen down at the root level.
OK, I've overwhelmed you with information and possibilities, let me simple tell you how I just prepared a terraced flower bed in my own front yard that measured about 200 sq.ft. I put 20 bags of organic mulch over the bed, each were 1.5 cu.ft. in size. I sprinkled about 2 pounds of Start-N-Grow fertilizer on top of the mulch, 4 pounds of Soil Sulfur and 4 cu.ft of perlite. I went over the soil twice with my rototiller at the deepest setting, and planted.
It was a terraced bed so I didn't add gypsum: drainage was good. If you have hard soil I would add to this formula 100 pounds of gypsum. Don't worry, it sounds like a lot, but it's only two large bags.
I have terrible soil or rocks for a garden, what do I do? Raised beds, terraces and containers are an increasingly popular solution.
Raised beds are a good solution to many garden problems. They provide excellent drainage and, as a result, drier, warmer soil in spring and a longer growing season. Aesthetically, raised beds add strong lines and different heights to the garden, creating visual contrasts.
My favorite reason for raised beds is the ease on my back and knees. After knee surgery and most recently back surgery this has become a real issue. Having a ledge to sit on or simply having the working soil raised above current ground level makes it so much easier to work, fence out critters and water.
Although garden magazines typically show raised beds surrounded by timbers or railroad ties, this shoring is an aesthetic feature, not a horticultural requirement. Raised beds can be as simple as low mounds of earth with pathways between them, to ease maintenance. Whiskey or wine barrels have long been used in the area as simple raised beds.
Each year I import several truckloads of clay and iron containers from Asia. It's one of the fastest growing departments in my store. The largest sizes have been in demand because they are so easy to plant and garden. The added bonus is that they're decorative. And unlike Italian or Mexican pottery, Asian pots will last years out in our weather, or until you drop one.
The best advise I can give you when planting any container is: use a good quality potting soil and you'll find gardening will be easier.
Remember, with great soil, comes great gardens abounding in fruits and flowers. Until next week, I'll see you in the garden center.
Ken Lain is the owner of Watters Home and Garden Center and is an Arizona Certified Nursery Professional and Master Gardener.